/* CSS Standard Modern Styles System - Royal Blue Theme (宝蓝明艳风) */
    :root {
      --primary: #1d6bf3;
      --primary-dark: #0f4c81;
      --primary-light: #eff6ff;
      --accent: #2563eb;
      --text-main: #1e293b;
      --text-muted: #64748b;
      --bg-body: #f8fafc;
      --bg-card: #ffffff;
      --bg-alt: #f1f5f9;
      --border-color: #e2e8f0;
      --radius-sm: 8px;
      --radius-md: 14px;
      --radius-lg: 20px;
      --shadow-sm: 0 2px 8px rgba(15, 76, 129, 0.05);
      --shadow-md: 0 8px 24px rgba(15, 76, 129, 0.08);
      --shadow-lg: 0 16px 36px rgba(15, 76, 129, 0.12);
      --max-width: 1240px;
      --transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
    }

    * {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }

    html {
      scroll-behavior: smooth;
      font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
      background-color: var(--bg-body);
      color: var(--text-main);
      line-height: 1.6;
    }

    body {
      overflow-x: hidden;
      width: 100%;
      min-height: 100vh;
      display: flex;
      flex-direction: column;
    }

    a {
      color: var(--primary);
      text-decoration: none;
      transition: var(--transition);
    }

    a:hover {
      color: var(--primary-dark);
    }

    .container {
      width: 100%;
      max-width: var(--max-width);
      margin: 0 auto;
      padding: 0 20px;
    }

    /* Standard Button Styles */
    .btn {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 12px 28px;
      font-size: 15px;
      font-weight: 600;
      border-radius: var(--radius-sm);
      transition: var(--transition);
      cursor: pointer;
      border: 1px solid transparent;
      white-space: nowrap;
    }

    .btn-primary {
      background: linear-gradient(135deg, var(--primary), var(--primary-dark));
      color: #ffffff;
      box-shadow: 0 4px 14px rgba(29, 107, 243, 0.35);
    }

    .btn-primary:hover {
      color: #ffffff;
      transform: translateY(-2px);
      box-shadow: 0 6px 20px rgba(29, 107, 243, 0.45);
    }

    .btn-secondary {
      background-color: var(--primary-light);
      color: var(--primary-dark);
      border: 1px solid rgba(29, 107, 243, 0.2);
    }

    .btn-secondary:hover {
      background-color: #dbeafe;
      color: var(--primary-dark);
    }

    .btn-outline {
      background-color: transparent;
      color: var(--primary-dark);
      border-color: var(--primary-dark);
    }

    .btn-outline:hover {
      background-color: var(--primary-dark);
      color: #ffffff;
    }

    /* Typography Helpers */
    .section-title-wrap {
      text-align: center;
      margin-bottom: 48px;
    }

    .section-tag {
      display: inline-block;
      padding: 4px 14px;
      background-color: var(--primary-light);
      color: var(--primary-dark);
      font-size: 13px;
      font-weight: 700;
      border-radius: 20px;
      margin-bottom: 12px;
      letter-spacing: 0.5px;
    }

    .section-title {
      font-size: 32px;
      font-weight: 800;
      color: var(--text-main);
      letter-spacing: -0.5px;
    }

    .section-desc {
      font-size: 16px;
      color: var(--text-muted);
      max-width: 720px;
      margin: 12px auto 0;
    }

    /* Header Nav */
    .header {
      position: sticky;
      top: 0;
      z-index: 1000;
      background-color: rgba(255, 255, 255, 0.92);
      backdrop-filter: blur(12px);
      border-bottom: 1px solid var(--border-color);
      height: 72px;
      display: flex;
      align-items: center;
    }

    .header-inner {
      display: flex;
      align-items: center;
      justify-content: space-between;
      width: 100%;
    }

    .logo-container {
      display: flex;
      align-items: center;
      gap: 12px;
    }

    .ai-page-logo {
      height: 40px;
      width: auto;
      object-fit: contain;
    }

    .nav-links {
      display: flex;
      align-items: center;
      gap: 24px;
      list-style: none;
    }

    .nav-links a {
      font-size: 14px;
      font-weight: 600;
      color: var(--text-main);
    }

    .nav-links a:hover {
      color: var(--primary);
    }

    .header-actions {
      display: flex;
      align-items: center;
      gap: 14px;
    }

    .menu-toggle {
      display: none;
      background: none;
      border: none;
      font-size: 24px;
      color: var(--text-main);
      cursor: pointer;
    }

    /* Section Wrappers */
    .section {
      padding: 80px 0;
      position: relative;
    }

    .section-alt {
      background-color: var(--bg-alt);
    }

    /* HERO SECTION (PURE CSS - NO IMAGES) */
    .hero-section {
      padding: 100px 0 80px;
      background: radial-gradient(circle at 50% 0%, #ebf5ff 0%, #f8fafc 70%);
      text-align: center;
      position: relative;
      overflow: hidden;
    }

    .hero-badge-wrap {
      display: inline-flex;
      align-items: center;
      gap: 8px;
      padding: 6px 16px;
      background: #ffffff;
      border: 1px solid #bfdbfe;
      border-radius: 30px;
      font-size: 13px;
      color: var(--primary-dark);
      margin-bottom: 24px;
      box-shadow: var(--shadow-sm);
    }

    .hero-h1 {
      font-size: 40px;
      line-height: 1.25;
      font-weight: 900;
      color: var(--primary-dark);
      margin-bottom: 20px;
      letter-spacing: -0.5px;
    }

    .hero-subtitle {
      font-size: 18px;
      color: var(--text-muted);
      max-width: 800px;
      margin: 0 auto 36px;
      line-height: 1.7;
    }

    .hero-btn-group {
      display: flex;
      justify-content: center;
      gap: 16px;
      margin-bottom: 50px;
      flex-wrap: wrap;
    }

    .hero-stats-grid {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 20px;
      max-width: 1000px;
      margin: 0 auto;
    }

    .hero-stat-card {
      background: #ffffff;
      padding: 24px 16px;
      border-radius: var(--radius-md);
      border: 1px solid var(--border-color);
      box-shadow: var(--shadow-sm);
    }

    .hero-stat-num {
      font-size: 30px;
      font-weight: 800;
      color: var(--primary);
      margin-bottom: 4px;
    }

    .hero-stat-label {
      font-size: 13px;
      color: var(--text-muted);
      font-weight: 600;
    }

    /* Services & Models Grid */
    .models-cloud {
      display: flex;
      flex-wrap: wrap;
      gap: 10px;
      justify-content: center;
      margin-top: 30px;
    }

    .model-chip {
      background: #ffffff;
      border: 1px solid var(--border-color);
      padding: 8px 18px;
      border-radius: 20px;
      font-size: 14px;
      font-weight: 600;
      color: var(--text-main);
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
    }

    .model-chip:hover {
      border-color: var(--primary);
      color: var(--primary);
      transform: translateY(-2px);
    }

    /* Grid Layouts */
    .grid-2 {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 28px;
    }

    .grid-3 {
      display: grid;
      grid-template-columns: repeat(3, 1fr);
      gap: 28px;
    }

    .grid-4 {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 24px;
    }

    /* Cards */
    .card {
      background: var(--bg-card);
      border-radius: var(--radius-md);
      padding: 32px 24px;
      border: 1px solid var(--border-color);
      box-shadow: var(--shadow-sm);
      transition: var(--transition);
      display: flex;
      flex-direction: column;
    }

    .card:hover {
      box-shadow: var(--shadow-md);
      border-color: #cbd5e1;
      transform: translateY(-4px);
    }

    .card-icon {
      width: 48px;
      height: 48px;
      background: var(--primary-light);
      color: var(--primary);
      border-radius: var(--radius-sm);
      display: flex;
      align-items: center;
      justify-content: center;
      font-size: 22px;
      font-weight: 800;
      margin-bottom: 20px;
    }

    .card-title {
      font-size: 20px;
      font-weight: 700;
      margin-bottom: 12px;
      color: var(--text-main);
    }

    .card-desc {
      font-size: 14px;
      color: var(--text-muted);
      flex-grow: 1;
      line-height: 1.6;
    }

    /* Comparison Section */
    .rating-badge {
      display: flex;
      align-items: center;
      justify-content: center;
      gap: 16px;
      background: #ffffff;
      padding: 16px 32px;
      border-radius: 40px;
      border: 1px solid #bfdbfe;
      width: fit-content;
      margin: 0 auto 36px;
      box-shadow: var(--shadow-sm);
    }

    .stars {
      color: #f59e0b;
      font-size: 20px;
    }

    .score-text {
      font-size: 18px;
      font-weight: 800;
      color: var(--primary-dark);
    }

    .table-container {
      width: 100%;
      overflow-x: auto;
      background: #ffffff;
      border-radius: var(--radius-md);
      border: 1px solid var(--border-color);
      box-shadow: var(--shadow-sm);
    }

    .custom-table {
      width: 100%;
      border-collapse: collapse;
      text-align: left;
      font-size: 14px;
    }

    .custom-table th, .custom-table td {
      padding: 16px 20px;
      border-bottom: 1px solid var(--border-color);
    }

    .custom-table th {
      background: var(--bg-alt);
      font-weight: 700;
      color: var(--text-main);
    }

    .custom-table tr:hover {
      background-color: #f8fafc;
    }

    .highlight-col {
      background-color: #eff6ff;
      font-weight: 700;
      color: var(--primary-dark);
    }

    /* Steps Timeline */
    .steps-wrap {
      display: grid;
      grid-template-columns: repeat(4, 1fr);
      gap: 20px;
      position: relative;
    }

    .step-item {
      background: var(--bg-card);
      padding: 24px;
      border-radius: var(--radius-md);
      border: 1px solid var(--border-color);
      position: relative;
    }

    .step-num {
      width: 36px;
      height: 36px;
      background: var(--primary);
      color: #ffffff;
      border-radius: 50%;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 800;
      margin-bottom: 16px;
    }

    /* Cases Showcase Gallery */
    .case-card {
      background: var(--bg-card);
      border-radius: var(--radius-md);
      overflow: hidden;
      border: 1px solid var(--border-color);
      box-shadow: var(--shadow-sm);
    }

    .case-img-wrap {
      width: 100%;
      height: 220px;
      overflow: hidden;
      background-color: #e2e8f0;
    }

    .case-img-wrap img {
      width: 100%;
      height: 100%;
      object-fit: cover;
      transition: var(--transition);
    }

    .case-card:hover .case-img-wrap img {
      transform: scale(1.05);
    }

    .case-content {
      padding: 20px;
    }

    /* Reviews Section */
    .review-user {
      display: flex;
      align-items: center;
      gap: 12px;
      margin-top: 20px;
      padding-top: 16px;
      border-top: 1px solid var(--border-color);
    }

    .avatar-placeholder {
      width: 40px;
      height: 40px;
      border-radius: 50%;
      background: var(--primary);
      color: #ffffff;
      display: flex;
      align-items: center;
      justify-content: center;
      font-weight: 700;
      font-size: 14px;
    }

    .user-info h4 {
      font-size: 14px;
      font-weight: 700;
    }

    .user-info p {
      font-size: 12px;
      color: var(--text-muted);
    }

    /* FAQ Accordion */
    .faq-list {
      max-width: 900px;
      margin: 0 auto;
      display: flex;
      flex-direction: column;
      gap: 14px;
    }

    .faq-item {
      background: #ffffff;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-sm);
      overflow: hidden;
    }

    .faq-question {
      width: 100%;
      padding: 18px 24px;
      text-align: left;
      background: none;
      border: none;
      font-size: 16px;
      font-weight: 700;
      color: var(--text-main);
      display: flex;
      justify-content: space-between;
      align-items: center;
      cursor: pointer;
    }

    .faq-answer {
      max-height: 0;
      overflow: hidden;
      transition: max-height 0.3s ease;
      background: #f8fafc;
      border-top: 1px solid transparent;
    }

    .faq-answer-inner {
      padding: 18px 24px;
      font-size: 14px;
      color: var(--text-muted);
      line-height: 1.7;
    }

    .faq-item.active .faq-answer {
      max-height: 300px;
      border-top-color: var(--border-color);
    }

    .faq-icon {
      font-size: 18px;
      transition: transform 0.3s ease;
    }

    .faq-item.active .faq-icon {
      transform: rotate(45deg);
    }

    /* Form Section */
    .form-box {
      background: #ffffff;
      padding: 40px;
      border-radius: var(--radius-lg);
      border: 1px solid var(--border-color);
      box-shadow: var(--shadow-md);
      max-width: 760px;
      margin: 0 auto;
    }

    .form-grid {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 20px;
    }

    .form-group {
      display: flex;
      flex-direction: column;
      gap: 6px;
    }

    .form-group.full-width {
      grid-column: span 2;
    }

    .form-group label {
      font-size: 14px;
      font-weight: 600;
      color: var(--text-main);
    }

    .form-control {
      padding: 12px 16px;
      border: 1px solid var(--border-color);
      border-radius: var(--radius-sm);
      font-size: 14px;
      outline: none;
      transition: var(--transition);
      background-color: var(--bg-body);
    }

    .form-control:focus {
      border-color: var(--primary);
      background-color: #ffffff;
      box-shadow: 0 0 0 3px rgba(29, 107, 243, 0.15);
    }

    /* Articles / News */
    .article-links {
      display: grid;
      grid-template-columns: repeat(2, 1fr);
      gap: 16px;
      margin-top: 24px;
    }

    .article-item {
      background: #ffffff;
      padding: 16px 20px;
      border-radius: var(--radius-sm);
      border: 1px solid var(--border-color);
      display: flex;
      justify-content: space-between;
      align-items: center;
    }

    /* Footer */
    .footer {
      background: #0f172a;
      color: #94a3b8;
      padding: 60px 0 30px;
      border-top: 1px solid #1e293b;
      margin-top: auto;
    }

    .footer-grid {
      display: grid;
      grid-template-columns: 2fr 1fr 1fr 1.5fr;
      gap: 40px;
      margin-bottom: 40px;
    }

    .footer-brand h3 {
      color: #ffffff;
      font-size: 20px;
      margin-bottom: 12px;
    }

    .footer-brand p {
      font-size: 14px;
      line-height: 1.6;
    }

    .footer-col h4 {
      color: #ffffff;
      font-size: 16px;
      margin-bottom: 16px;
    }

    .footer-col ul {
      list-style: none;
      display: flex;
      flex-direction: column;
      gap: 10px;
    }

    .footer-col a {
      color: #94a3b8;
      font-size: 14px;
    }

    .footer-col a:hover {
      color: #ffffff;
    }

    .qr-box {
      background: #ffffff;
      padding: 10px;
      border-radius: var(--radius-sm);
      display: inline-block;
      margin-bottom: 8px;
    }

    .qr-box img {
      width: 100px;
      height: 100px;
      display: block;
    }

    .friendship-links {
      padding-top: 24px;
      border-top: 1px solid #1e293b;
      display: flex;
      flex-wrap: wrap;
      gap: 16px;
      font-size: 13px;
    }

    .friendship-links a {
      color: #64748b;
    }

    .friendship-links a:hover {
      color: #38bdf8;
    }

    .copyright {
      text-align: center;
      padding-top: 24px;
      font-size: 13px;
      color: #64748b;
    }

    /* Floating Widget */
    .floating-widget {
      position: fixed;
      right: 20px;
      bottom: 30px;
      z-index: 999;
      display: flex;
      flex-direction: column;
      gap: 10px;
    }

    .float-btn {
      width: 48px;
      height: 48px;
      border-radius: 50%;
      background: var(--primary);
      color: #ffffff;
      display: flex;
      align-items: center;
      justify-content: center;
      box-shadow: var(--shadow-lg);
      cursor: pointer;
      font-weight: 700;
      border: none;
      transition: var(--transition);
    }

    .float-btn:hover {
      transform: scale(1.1);
    }

    /* Responsive adjustments */
    @media (max-width: 1024px) {
      .hero-stats-grid { grid-template-columns: repeat(2, 1fr); }
      .grid-4 { grid-template-columns: repeat(2, 1fr); }
      .steps-wrap { grid-template-columns: repeat(2, 1fr); }
      .footer-grid { grid-template-columns: repeat(2, 1fr); }
    }

    @media (max-width: 768px) {
      .nav-links {
        display: none;
        position: absolute;
        top: 72px;
        left: 0;
        right: 0;
        background: #ffffff;
        flex-direction: column;
        padding: 20px;
        border-bottom: 1px solid var(--border-color);
        box-shadow: var(--shadow-md);
      }

      .nav-links.active { display: flex; }
      .menu-toggle { display: block; }
      .hero-h1 { font-size: 28px; }
      .hero-subtitle { font-size: 15px; }
      .grid-3, .grid-2 { grid-template-columns: 1fr; }
      .form-grid { grid-template-columns: 1fr; }
      .form-group.full-width { grid-column: span 1; }
      .footer-grid { grid-template-columns: 1fr; }
      .steps-wrap { grid-template-columns: 1fr; }
      .article-links { grid-template-columns: 1fr; }
    }